Santhera Pharmaceuticals has decided to discontinue its Phase III SIDEROS trial of Puldysa (idebenone) in patients with Duchenne muscular dystrophy (DMD).

The move comes after an independent Data and Safety Monitoring Board (DSMB) reviewed interim data and found that the trial is not likely to meet its primary goal.

During the interim analysis, the DSMB reviewed the efficacy of the drug candidate in DMD patients who are in respiratory decline and on concomitant glucocorticoid treatment.

The primary endpoint was the change of forced vital capacity percentage predicted (FVC%p) from baseline to 18 months of treatment.

With the interim data showing narrow probability in meeting the primary endpoint at the end of the study, DSMB advised discontinuing the trial citing its futility. Data did not reveal any safety concerns.

After the discontinuation of the trial, enrolled participants will stop taking study medication and complete the  follow-up assessments.

The company intends to analyse the impact of discontinuation on current expanded access programmes with relevant regulatory agencies.

The data prompted Santhera to plan a restructuring, shifting its focus on another DMD drug candidate vamorolone and execute on its other pipeline programmes.

Santhera will also withdraw the European marketing authorisation application and halt the global development of Puldysa.

Santhera Pharmaceuticals CEO Dario Eklund said: “While this is obviously not the outcome we expected, all our efforts in DMD will now be focused on progressing the promising drug candidate vamorolone which we recently licensed from ReveraGen to its next inflection point, the readout of six-month top-line data from the pivotal VISION-DMD study planned for the second quarter of 2021.”

Apart from progressing vamorolone, Santhera also plans to focus on lonodelestat for cystic fibrosis and other lung diseases, along with its discovery-stage gene therapy method for congenital muscular dystrophy.